Jay Hatch started his day on Thursday watching a little golf at the John Deere Classic. He ended it as a Quad Cities celebrity after an unexpected stint as a caddie for co-leader Brian Harman.

Harman was cruising along at 2 under through six holes when his caddie, Scott Tway, who had been feeling poorly overnight, couldn't continue.

"I called a medic over and Scottie said he was going to have to sit out at least a couple holes," Harman said after posting a first-round 63 – his best score of the year by two shots. "Jay was standing there and said, 'I'll do it. I'll keep up.' "

Hatch grabbed the bag, and did more than keep up. He helped Harman go 6 under on his final 12 holes and finish the day tied fore the lead with Zach Johnson and Rory Sabbatini.

Hatch, it turns out, is a coach at Alleman High School in nearby Davenport, Iowa, whose teams have won three girls' state softball titles and one girls' state basketball crown.

"I don't know how athletic it was, but it was sure cool," said Hatch, who towered over the 5-foot-7 Harman. "I always wanted to be inside the ropes to see what it looked like from there. You know that commercial where they say 'These guys are good?' They are way, way better than that."

Hatch, who also plays some recreational golf, told Harman, "I can carry your bag if you don't need any help reading putts." Harman also checked his own yardages for the rest of the round.

Afterward, Harman was thrilled with the performance of his surprise substitute.

"My man Jay came out and did a really good job. He was like a true pro out there," said Harman, who vowed to send Hatch a check for his effort. Hatch, however, quickly declined the offer, and Tway is expected to be back on the bag on Friday afternoon for Harman's second round.